Added build information (build date/time, git commit point) into the library

Signed-off-by: Austin Yuan <shengquan.yuan@intel.com>

src/Makefile.am

@@ -30,6 +30,16 @@ libva_la_LDFLAGS = -version-number 0:30:0 -no-undefined
 libva_la_LIBADD = $(LIBVA_LIBS) -ldl -ldrm -lX11 -lXext -lXv X11/libva_X11.la
 CFLAGS = -ansi -O2 
 
+nodist_libva_la_SOURCES = va_version.h
+BUILT_SOURCES = va_version.h
+
+CLEANFILES = va_version.h
+
+va_version.h: Makefile
+	echo "#define VA_BUILD_DATE \"$(shell date +'%Y%m%d') $(shell date +'1%H%M%S') \"" > va_version.h
+	echo "#define VA_BUILD_GIT  \"($(shell git log  | head -n1 | cut -f2 -d' ')) \" "    >> va_version.h
+
+
 SUBDIRS = X11
 
 libva_la_SOURCES = va.c 

src/va.c

@@ -25,6 +25,8 @@
 #include "va.h"
 #include "va_backend.h"
 
+#include "va_version.h"
+
 #include <assert.h>
 #include <stdarg.h>
 #include <stdio.h>
@@ -32,6 +34,8 @@
 #include <dlfcn.h>
 #include <unistd.h>
 
+#define VA_STR_VERSION		VA_BUILD_DATE VA_BUILD_GIT
+
 #define VA_MAJOR_VERSION	0
 #define VA_MINOR_VERSION	30
 #define DRIVER_INIT_FUNC	"__vaDriverInit_0_30"
@@ -325,6 +329,8 @@ VAStatus vaInitialize (
 
   va_debug_trace = (getenv("LIBVA_DEBUG_TRACE") != NULL);
 
+  va_infoMessage("libva build on %s\n", VA_STR_VERSION);
+
   vaStatus = va_getDriverName(dpy, &driver_name);
   va_infoMessage("va_getDriverName() returns %d\n", vaStatus);